Frame construction for playgyms



1956 D. scARAMuccn FRAME CONSTRUCTION FOR PLAYGYMS 2 Sheets-Sheet 1Filed Dec. 16, 1952 INVENTOR.

ATTORNEYS p 1956 D. SCARAMUCCI 2,763,455

FRAME CONSTRUCTION FOR PLAYGYMS Filed Dec. 1e, 1952 2 Sheets-Sheet 2United States Patent FRAME CONSTRUCTION FOR PLAYGYMS Domer Scaramucci,Oklahoma City, Okla.

Application December 16, 1952,'S erial No. 326,229

Claims. (Cl.287--54) This invention relates generally to swings,playgyms, gliders, etc. which include spaced pairs of supporting legsconnected by a top bar and more particularly to a coupling forconnecting the top bar and its supporting legs.

Couplings of this type are known in the art and due to the severestresses to which they are subjected during use of the swings andsimilar equipment, have proven to be unsatisfactory because of earlyfailure due to lack of strength, lack of rigidity of the frame, poordesign, and

excessive costs due to the necessity for using castings, heavier andmore complex members and .difiicult'y of manufacture of the same.

The legs and frame members of swing structures are usually tubular andin oneprior art construction, the ends of the tubular bar and legs areflattened, .aper-tured, and joined by bolts. Another constructioninvolves the bolting of arcuate plates to the ends of the top bar andflattening and conforming the upper ends of the legs thereto andwelding. In either case, the movement of a swing and particularly one ofthe parallel bar type, results in a strong torque tending to oscillatethe top bar which flexes the flattened portions, and loosening andbreakage soon results even though, in the latter case, heavier tubemembers must necessarily be used.

The use of short lengths of heavy tubing as sockets-for the ends of thelegs and top bar is also known in various forms and differ mainly .intheir fabrication, cast socket designs being excessively costly andrarely employed. Such heavy tube sockets are cut at one end to conformwith the top bar, andset screws .are set in the leg sockets to retainthe legs in operative position. While this more expensive constructionpartially eliminates the twisting and loosening at the top bar, anotherserious problem is created in that the twisting stresses areconcentrated at the set screws. These stresses are increased by theanchoring of the legs to the ground to prevent tipping and the setscrews gouge through the tubular legs and Work loose so that positivelocking cannot be achieved.

Accordingly, the chief object of the present invention is to provide animproved coupling for the top bar and legs of swing and playgymstructures which will obviate the disadvantages characterizing knownprior art structures.

Another important object of the present invention is to provide animproved coupling which will continuously withstand the severe torsionalforces acting on the top bar and legs through use of the swings withoutloosening or failure thereof.

A further important object is to provide an improved coupling of thetype described which will act as a positive leg fastening means and alsobrace and steady the frame even when used with lighter tubes.

A still further important object is to provide an improved coupling fortop bars and their supporting legs in which the twisting stressestransmitted from the bar will be distributed throughout the portion ofthe tube held by the coupling.

Another object is to provide an improved coupling of 'ice the typedescribed which may be readily and economically manufactured vand oflong life in use.

"the invention. In these showings;

Fig. 1 is a perspective view of a swing set or playgym employing thecoupling comprising the present invention;

Fig. 2.15 a plan view :to an enlarged scale of the blank fromwhich thecoupling is formed;

Fig. 3 is a fragmentary side elevational view showing .theformedcoupling fixed in operative position on the end of the top bar;

Fig. 4 is an end :.elevationalview thereof;

Fig. 5 is a bottom view thereof;

Fig. 6 is a fragmentary perspective view thereof;

Fig. 7 is a side elevational view of a modified form .of the invention;

Fig. 8 is an end elevational view thereof;

Fig. 9 is an end elevational view of a further modification of theinvention; and

Fig. 1.0 is a side elevational view of a still further modification ofthe invention.

Referring to Fig. 1 of the drawings, numeral 12 designates a swing setor playgym as a whole which includesa pair of .chain supported swings 14and a parallel .b ar swing 16, all supported by .a .top tube or bar 18connected with spaced pairs of diverging legs 20 by means of thecouplings also indicated as a whole as 22. The

pairs of legs are braced intermediate their lengths by connecting bars24. The top bar and legs are usually and preferably formed of strongsteel tubing.

aligned when a .bolt 28 is slipped therethrough. A pair of diyerging legtube receiving sockets are thus formed -.(.Fi gs. 3:6 incl.) connectedby overlying spaced, intervening webs and the angle of divergenceissupplementary to the angle formed between the lines from the wingapertures to the central aperture before bending.

It will be noted that the notch 25 forms a supporting shoulder for oneend of the top bar 18 which is closed by the overlapped wings 26 and thetwo members are welded together along their entire line of contactincluding the shoulder 25 and the wings 26. A second coupling 22 issimilarly fixed to the other end of the tube 18.

In assembling the legs to the top bar and coupling unit thus formed,which may be done at the site of intended use of the swing, etc., theupper ends of each pair of legs are inserted in the diverging socketsformed in the couplings 22. The brace bars 24 are next fixed to the legsin order that the frame may be prestressed when the couplings are thentightened.

The tightening of the single bolt 28 of each coupling 22 draws the webstoward each other and tends to wrap the socket about each leg so thatupon final tightening, the socket is held in tension about the leg whichis in a state of compression. Thus, the stresses are evenly distributedthroughout the leg tube and are not concentrated at any single point.

The coupling provides a prestressing of the frame which insures itscontinued rigidity as well as a positive leg gripping with distributedstresses. As seen in Fig. 6, the tightening of the bolt 28 sets upforces generally indicated as x which tend to close the vertex angle yformed by the legs. The forces x are adequately resisted by the bracebars 24 which is thus prestressed in compression by the tightening ofthe bolt and any slack is permanently eliminated. Y

The Figs. 7 and 8 disclose a slightly modified form of the invention inwhich the coupling 30 is stamped from a blank so shaped as not to closethe end of the tube 18 but to provide a pair of notches to conform withthe bottom thereof. The coupling 30 and the tube 18 are joined bywelding as before and inwardly of the end of the tube; and the end mayor may not be closed as desired.

Fig. 9 discloses a form of the invention which embodies the principlesdescribed but which permits, by the use of a pair of bolts 28, theaccomplishment of the wrap around principle of the coupling 32separately with respect to each leg.

The disclosure of Fig. 10 is almost identical with that of Figs. 16incl. but differs in that the wings 26 terminate and overlap on theinside of the coupling 34 rather than on the outside as disclosed in thecoupling 22.

It will now be readily apparent that the improved coupling comprisingthe present invention provides a continued, positive clamping of thetubular legs with an even distribution of the stresses thereto;eliminates the need of making and installing an end cap for the top bar;permits the use of lighter tube members as the sockets grip the legsevenly so as to minimize crushing, distortion or failure and throughprestressing increase the rigidity of the coupling; and promotes economyin fabrication through the use of stamped plate instead of castings orspecially cut heavy tubes.

It is to be understood that the forms of the invention herewith shownand described are to be taken as preferred examples of the same and thatvarious changes in the shape, size and arrangement of parts may beresorted to without departing from the spirit of the invention or thescope of the subjoined claims.

I claim:

1. A coupling for the ends of the horizontal top tube and divergent legsof swing frames, etc. comprising a single, one-piece, elongated sheetmetal body notched at the center of one long side and configured toprovide edges to closely receive and conform to a portion of the wallsof the top tube along an irregular line substantially angled to the axisof the tube and adapted to be welded thereto along the engaging edges,said body sheet beyond said notch defining a pair of merging butdivergent leg receiving sockets directed to hold the ends of the legsagainst said top tube opposite the edge connections thereto, andintervening webs edge connected to the sockets and overlying and spacedapart, and means to draw said webs toward each other to tension bothsockets about the leg ends.

2. The coupling of claim 1 in which said webs are integral extensions ofthe sheet material of the sockets and a single bolt is positioned todraw them toward each other to increase the tension about the leg endsand simultaneously apply decreasing angle of divergence tension to thesockets. I

3. The coupling of claim 2 in which one of said webs comprisesoverlapping portions of said sheet metal body each perforated for saidbolt whereby leg gripping tension is applied separately to each socket.

4. For use in a frame for swings, etc. having a top tube, a pair ofsupporting divergent tubular legs and a connecting brace bar between thelatter, the combination of a one-piece sheet metal coupling permanentlyfixed to the top tube adjacent to and covering one end thereof, saidcoupling having a shape to form a pair of divergent leg tube receivingsockets each substantially open where it faces the other, one edge ofeach opening being connected' by a continuous web and each other edgehaving a web extending therefrom and overlapping that from the other,said continuous and overlapping webs being spaced apart and means todraw them toward each other to clamp the leg tubes and to simultaneouslytend to reduce the angle of socket divergence whereby the brace bar isplaced under compression.

5. The device of claim 4 in which said coupling sheet is notched toreceive and closely support the end portion of the top tube and meanswelding the edges of the notch to the walls of the top tube to integratethese parts.

References Cited in the file of this patent UNITED STATES PATENTS600,276 Crosby et a1. Mar. 8, 1898 1,223,717 Mintz Apr. 24, 19171,380,468 Drew June 7, 1921 1,470,627 Lamplugh Oct. 16, 1923 1,949,197Cornell Feb. 27, 1934 2,603,272 Rowand July 15, 1952 FOREIGN PATENTS 7671,520 France Dec. 13, 1929 860,901 France n v t v Jan. 28, 1941

